The Pond Hall Building of the Thorp Receipt and Storage Facility at Sellafield houses two large water ponds as part of the reprocessing of spent uranium rods.
Rods arrive at Sellafield from all over the world. They are placed in flask containers and lowered into the ponds. They stay in the ponds for a predetermined period to allow for cooling and then undergo a separation process that recovers good fuel, which can be re-used.
The building is 36 metres tall, 192 metres along two elevations and 45 metres long at gable ends. It has two distinct roofs - one consisting of natural asphalt on a deck, the other featuring the Tata Steel KalZip® standing seam system. Its moist internal atmosphere creates an extremely similar high humidity environment to that of a swimming pool. It is also located in an extremely aggressive marine location, a few hundred yards from the Irish Sea. Sellafield Ltd carried out performance analysis of the building envelope. Concerns were expressed over the potential long term integrity of the single-skin aluminium sheeting on the walls, as signs were emerging that suggested it would eventually require replacement. As an initial step, over 28,000 fixings were replaced, maintaining current performance levels while Sellafield Ltd sought an appropriate permanent solution. Preston-based contractor F Brown plc were approached with a view to putting forward an acceptable wall cladding replacement option. Mitch Dunne, F Brown’s Project Manager, takes up the story: “We worked closely with Tata Steel to establish a solution that would provide a long term answer to controlling the relatively unusual mixture of aggressive internal and external environments. “We carried out a lot of work in conjunction with the Tata Steel technical department. Following extensive evaluation, Sellafield Ltd accepted our suggestion of the Trisomet® 333 System insulated wall panel system in double-sided Colorcoat HPS200 Ultra® pre-finished steel, covered by the Tata Steel Platinum System Warranty.” Featuring a straightforward side-lapping detail, the Trisomet® 333 System affords faster installation and a broad pan trapezoidal pre-finished steel external profile. F Brown plc is an approved installer within the Platinum Warranty scheme. This means that their workmanship is continually checked to ensure everything is being correctly installed. The warranty provides peace of mind to clients for up to 25 years. It is free of charge, covers material performance and workmanship and provides the client with a direct link to Tata Steel in the unlikely event of a problem. The warranty covers all building envelope solutions provided by Tata Steel, making it the most comprehensive system warranty available. All components used are covered under the warranty through supply chain partnerships.